In recent years, the use of barley straw has become more common as an alternative method for controlling excessive algae growth.

Barley straw does not kill algae, but it inhibits the new growth.When exposed to sunlight and in the presence of oxygen, it produces a chemical that inhibits algae growth. Barley straw does not reduce the growth of other aquatic plants and in some cases aquatic plant growth has increased after barley straw applications because algae are no longer present to compete with the aquatic plants.

Applications of barley straw are most effective when applied early in the year prior to the appearance of algae (fall through early spring). Depending on the temperature, it can take six to eight weeks for the straw to begin producing the active chemicals that inhibit algae growth.